The invention relates to optical disk recording, and more particularly, to systems and methods for optimizing write strategy parameters using two-stage adjustment.
In order to precisely reproduce the data signals, the laser power control pulse, such as the pulse width, pulse shape and power level of laser output, are must be precisely controlled to record stable and accurate marks on an optical disk. The laser power level is typically acquired by an optimal power calibration (OPC) procedure. Optimal write parameters for the width and shape of laser output are typically achieved by repeatedly adjusting so-called write strategies.
Before an optical disk recorder leaving a factory, the manufacturer would setup a plurality of optimum write strategies for various optical disks, and store the optimum write strategies individually with a disk identity in a built-in table embedded in the optical disk recorder. When recording data, the optical disk recorder reads a corresponding write strategy from the built-in table according to a disk identity of a loaded optical disk and performs the conventional OPC procedure to acquire an optimal write power level. The conventional method has several drawbacks. First, there always has manufacturing difference between the optical disks or the optical disk recorders, so the optimal write strategy for recording the marks may be diverged from the best setting. Even the optimal power level has determined by the OPC procedure, the marks may not be recorded well and the recording quality maybe unreliable, due to the variations of the optical disks or optical disk recorders. Second, the optical disk recorders may consume excessive storage space to support all possible optical disk types. And this will also need a large number of human powers to adjust the optimal write strategies for the all possible optical disk types. Large storage space and large number of human powers will also cost a lot. Moreover, there always have new types of optical disks being manufactured. Due to the limited storage space and limited human power, the optical disk recorder can not support all optical disk types. Then, the optical disk recorder is restricted in practicability.
In order to determine optimum write strategy for unsupported optical disks, conventional methods may first perform several trial recordings using different write strategies and subsequently determine a better write strategy therefrom according to several write quality indices.